Typography calculator
REM, EM, and PX Converter
Convert rem to px, px to rem, and em to px using your root font size for consistent typography scales, spacing tokens, and design system implementation.
Root font size
rem → px
Result
16.0000px
px → rem
Result
1.000000 rem
em → px
em is relative to the parent element's font size. Set the parent font size in px below.
Result
16.0000px
Quick reference
rem is relative to the root element (html).em is relative to the current font context and can compound.
Need display density? Try the PPI calculator or breakpoint checker.
Default root size
Browsers often default to 16px on root. If your site sets html { font-size }, adjust the root field so rem math matches production values.